Cool Air

ARTICLES ABOUT COOL AIR BY DATE - PAGE 4

It was midafternoon on one of the hottest days of the year, and the thermometer in Marianne Zornig's second-floor apartment read 90 degrees. Her window-unit air conditioner had conked out more than a month earlier. Zornig concedes the air conditioner had seen better days. The Chicagoan had bought it 15 years ago from Sears, but she maintained an updated service contract. Despite repeated calls to Sears, she could not get the unit fixed. "When I originally called on June 8, [the temperature]

Lying still in a darkened bedroom Sunday morning, Rose Czoty tried to keep cool. Nearly eight hours had passed since the hum of her window air-conditioning unit went silent, when the power went out on a block of bungalows lining North Neva Avenue in Chicago's Montclare neighborhood. For Czoty, who has multiple sclerosis, the hot, thick air was aggravating her symptoms, making the heat wave even more unbearable. "I'm just worried about my medication in the fridge," said Czoty, 47. "It's $2,000 just for a month's prescription.

Most of us feel comfortable when air in the house is only moderately moist--between 30 and 50 percent relative humidity. Nature takes care of that on its own sometimes. But in the winter you have to add a little moisture and now in the summer you have to remove it--in some houses by the bucketful. Here are the three best ways to do it. - Vent moisture where it's made. Normal household operations like cooking and washing produce 7 to 10 gallons of moisture every day. That's in addition to moisture that's already in the air as humidity.

In meteorological parlance, a "front" is the boundary between air masses of differing characteristics, most commonly temperature and moisture content. A front is termed "cold" when it marks the leading edge of an advancing mass of air that is cooler than the air it is replacing, "warm" when warmer air is replacing cooler air, and "stationary" when the boundary is motionless. Frontal boundaries are the leading producers of rainfall in the Earth's middle latitudes. 1. SATURDAY NIGHT: Chicago's next significant chance of rain comes in association with a cold front approaching from the northwest.

Dear Tom, On a warm day recently, there was a lake breeze even though it is now mid-autumn. How is this possible? Phil Westraul Dear Phil, The fundamental cause of wind is unequal heating of the air, and this implies that some bodies of air will become warmer than others. When at the same elevation, a given volume of cool air, because it is more dense, always weighs more than an equal volume of warmer air. The greater weight of cool air causes it to exert greater pressure.

Northernmost North America, bathed in round-the-clock sun only three months ago, has watched daily sunlight dwindle 13.4 hours since the hemisphere's longest day, June 21. Eight minutes of sun vanishes there each day this time of year, making it the perfect breeding ground for cool air masses, like the one which has settled across much of the country in recent days. The chill's arrival has prompted severe weather in sections of 13 states over the past two days and has delivered frosty nighttime 20s to the higher elevations of the West, strengthening storm-generating jet stream winds in the process.

When really steamy weather arrives, it's hard to make a case for anything but an overwhelming supply of central air conditioning. But portables have a place--and if you have central air already, so do zone controls. Both deliver cool, dry air where you need it, when you need it. That's more economical than unrestricted central air that cools bedrooms as much as stairwells and closets. Portable AC Among hundreds of portables on the market, the main distinctions are installation method and cooling capacity.

Thursday's 91(degrees) high at Midway marked the 27th reading above 90(degrees) this year. The pace at which 90s have occurred in recent months has been torrid compared to the four recorded just a year ago. Highs reached 90(degrees) Thursday at Waukegan (90(degrees)), Gary (91(degrees)), Kankakee (90(degrees)) and Wheeling (92(degrees)). While Friday's humidity drop offers Chicagoans a welcome break, heat and humidity return early next week. But, a huge pool of unseasonably cool air is to develop across the eastern two-thirds of Canada in the next 1-2 weeks, strengthening a jet stream racing west to east across the northern Midwest.

Our favorite spot in our house is the screened-in porch. When we designed our house, we wanted the porch to be a focal point. At 15 feet by 19 feet, it is large enough to hold a summer get-together or a sit-down dinner for 10. All in an insect-free environment. One of the highlights of spring is the day that we open up the porch and set up the furniture. In the fall it is so sad when we have to close it down. The porch faces east, so we get the morning sun--which makes it great for relaxing breakfast meals.